1. Field of Invention
The present invention relates to an orientation-adjusting device. More specifically, it relates to an orientation-adjusting device for adjusting orientation of a surface texture measuring tool or a workpiece, the surface texture measuring tool having a surface texture detecting sensor for detecting a surface texture of a workpiece such as surface roughness, waviness and profile, and a driver for moving the surface texture detecting sensor in a base line direction. The present invention includes a device for searching and adjusting a tilt angle of the center locus of a measured value of the roughness, waviness and profile to a base line.
2. Description of Related Art
A surface texture measuring tool having a surface texture detecting sensor for detecting surface texture of a workpiece such as surface roughness and a driver for moving the surface texture detecting sensor in a base line direction is conventionally known.
A problem associated with the surface texture measuring tool is that, when the base line for the surface texture detecting sensor to move on (also referred to as a base line of the driver) is not parallel with the surface of the workpiece, measurement data of the surface texture detecting sensor can rise rightward or leftward, thus exceeding a measurement range of the surface texture detecting sensor. Especially, when the workpiece is measured at high resolution, since the measurement range of the surface texture detecting sensor is narrowed, the measurement data is likely to exceed the measurement range when the surface of the workpiece and the base line of the driver are not parallel.
For solving the above problem, a roughness measuring machine having an orientation-changing means for adjusting the orientation of the workpiece to parallel the surface of the workpiece and the base line of the driver has been proposed (Japanese Utility Model Publication Hei 4-19461).
The roughness measuring machine has a base, an orientation-changing means provided on the base for the workpiece to be put on, a column standing on the base and a roughness sensor vertically movable along the column.
The orientation-changing means has a support shaft standing on the base and a stage liftably supported by the support shaft for the workpiece to be put thereon, where the stage is lifted and lowered being supported by the legs as the supporting points, thus adjusting the orientation of the workpiece.
The roughness sensor has a surface texture detecting sensor for detecting surface roughness of the workpiece and a driver for moving the surface texture detecting sensor in a direction of a base line.
When a surface roughness of a workpiece is measured, a preliminary measurement is conducted for detecting inclination on the surface of the workpiece. During the preliminary measurement, while the workpiece is rested on the stage, the surface texture detecting sensor is moved along the surface of the workpiece to obtain a surface locus of the surface of the workpiece. By calculating a center line of the surface locus, an inclination compensation amount, i.e. a compensation amount to parallel the surface of the workpiece with the base line, can be calculated from the inclination of the center line, and the stage is lifted or lowered for the compensation amount. As a result, since the surface of the workpiece becomes substantially parallel with the base line of the roughness sensor, the surface texture can be measured within the measurement range of the roughness sensor, so that the surface texture can be measured at high resolution.
However, since the above-described orientation-changing means adjusts the orientation of the workpiece after putting the workpiece on the stage, the orientation-changing means can only be used for measuring a light workpiece smaller than the stage. For overcoming the above disadvantage, the size or rigidity of the orientation-changing means may be increased. However, if the orientation-changing means is enlarged, the size of the base for the orientation-changing means to be put on also has to be increased, so that the size of the entire device can be increased, thus being expensive and requiring large installation space.
An object of the present invention is to provide an orientation-adjusting device of a surface texture measuring device that can be used irrespective of the size of the workpiece and can be economically constructed.
An orientation-adjusting device according to the present invention is for adjusting an orientation of a surface texture measuring tool having a surface texture detecting sensor for detecting a surface texture of a workpiece and a driver for moving the surface texture detecting sensor in a direction of a base line. The orientation-adjusting device is characterized in having: a body for holding the surface texture measuring tool; an orientation adjuster having a leg rested on the workpiece, the orientation adjuster being capable of adjusting an orientation of the body by adjusting a height of the leg; and a height adjuster for vertically moving the surface texture measuring tool in parallel to the body.
According to the present invention, the orientation of the surface texture measuring tool can be adjusted in accordance with the inclination of the surface of the workpiece by adjusting the height of the respective legs of the orientation adjuster while the body holding the surface texture measuring tool is put on the workpiece through the orientation adjuster. In other words, the movement direction (base line direction) of the surface texture detecting sensor can be made parallel with the surface of the workpiece. Accordingly, even when the dimension of the workpiece is large, only a space for resting the body on the workpiece is necessary, so that the surface texture can be measured at high resolution without being restricted by the size of the workpiece. Furthermore, since the single orientation-adjusting device is used irrespective of the size of the workpiece, cost thereof can be reduced as compared to a conventional arrangement.
Further, since the height adjuster for vertically moving the surface texture measuring tool 1 in parallel with the body is provided to the orientation-adjusting device, the surface texture measuring tool can be located at an appropriate height position relative to the surface of the workpiece while the orientation of the surface texture measuring tool is adjusted.
In the orientation-adjusting device according to the present invention, the height adjuster preferably includes: a guide provided to the body; a slide member vertically slidable relative to the guide and having the surface texture measuring tool secured thereto; and an elevating mechanism for vertically moving the slide member along the guide.
According to the present invention, since the surface texture measuring tool is vertically moved along the guide through the slide member, the surface texture measuring tool can be easily and stably moved vertically while being in parallel with the body. Further, since the structure of the height adjuster is simple, production thereof can be facilitated.
In the orientation-adjusting device according to the present invention, the elevating mechanism may preferably include: a threaded shaft rotatably supported to the body, the threaded shaft being indisplaceable in an axial direction, the threaded shaft having one end screwed to the slide member and the other end projecting from the body; and a knob secured to the other end of the threaded shaft.
According to the present invention, when the knob of the height adjuster is rotated, the threaded shaft is rotated keeping the position thereof, thus vertically moving the slide member screwed to the threaded shaft. Accordingly, the surface texture measuring tool can be manually moved vertically, and structure thereof is simpler as compared to the arrangement having a motor etc., thus reducing production cost thereof.
In the orientation-adjusting device according to the present invention, the orientation adjuster may preferably include: first and second legs height adjustably screwed to one end of the body on both sides of the base line; and a third leg height adjustably screwed to an opposing end of the body on the base line.
According to the present invention, since the orientation adjuster has the first leg and the second leg screwed to one end of the body and on both sides of the base line with its height being adjustable, and the third leg screwed to the other end of the body on the base line with its height being adjustable, the orientation-adjusting device can be rested on a workpiece having a cylindrical outer surface etc. in a well-balanced manner. Further, the body (i.e. the surface texture measuring tool) can be inclined in the base line direction by adjusting the height of the third leg relative to the first and the second legs, and the body can be inclined in a direction orthogonal with the base line by adjusting the height of the first and the second legs. Further, by adjusting the height of the first and the second legs, the orientation-adjusting device can be rested on a cylindrical workpiece having a different diameter in a well-balanced manner.
In the orientation-adjusting device according to the present invention, the orientation-adjusting device may preferably be detachable from the surface texture measuring tool.
According to the present invention, since the orientation-adjusting device is detachable relative to the surface texture measuring tool, the orientation-adjusting device may be attached to the surface texture measuring tool only when the orientation of the surface texture measuring tool is necessary to be adjusted, thus enabling application of the orientation-adjusting device to a conventional surface texture measuring tool.
In the orientation-adjusting device according to the present invention, a flat portion capable of resting the workpiece may preferably be formed on an upper side of the body.
According to the present invention, since a flat portion capable of resting the workpiece thereon is formed on an upper side of the body, the orientation of the workpiece can be adjusted by using the orientation-adjusting device as the stage when the workpiece is small. In this case, the surface texture measuring tool may preferably be attached to a stand etc.